The invention relates generally to multimedia conferencing systems and more particularly, but not by way of limitation, to techniques (systems and methods) for controlling multimedia communication systems from a central control point using Internet Protocol (IP) trunking.
In the current market, most multipoint audio and/or multimedia calls are scheduled in advance through companies that own Multipoint Control Units (MCUs) or Audio Bridges. An MCU provides the capability for three or more terminals to participate in a multipoint audio and/or multimedia conference. An Audio Bridge provides the capability for three or more terminals to participate in a multipoint audio conference. The paragraphs that follow may also use the term “MCU” to refer to an audio bridge used for multipoint audio conferences; therefore, in the description words such as MCU and Audio Bridge may have the same meaning. A terminal is an end-point on a network, capable of real-time, two-way audio, data and/or visual communication with other terminals or an MCU. The information communicated between the terminals and/or the MCU includes control signals, indicators, audio moving color video pictures and/or data. A terminal may provide speech only, speech and data, speech and video, or speech, data and video. A more thorough definition of a terminal can be found in the International Telecommunication Union “ITU”) standards, such as but not limited to: H.320, H.321, H.324 and H.323. The ITU is the United Nations Specialized Agency in the field of telecommunications. The ITU Telecommunication Standardization Sector (ITU-T) is a permanent organ of the ITU. The ITU-T is responsible for studying technical, operating, and tariff questions and issuing recommendations on them with a view to standardizing telecommunications on a worldwide basis. Additional information regarding the ITU can be found at the website address of http://www.ITU.int. Other protocols that may be used over an IP network include the Session Initiation Protocol (SIP). More information about SIP may be found at the website http://www.IETF.org.
If a company owns more than one MCU or more than one audio bridge, it has more flexibility in hosting conferences. However, each MCU must be operated independently from the other MCUs in setting up and controlling conferences. Additionally, the capacity of each MCU is limited to conferences controlled by that MCU. The resources of the multiple MCUs cannot easily be combined to promote more efficient scheduling.
Traditionally, customers wishing to use a multipoint audio and/or multimedia conferencing service must reserve their conferences in advance. The customer must provide several parameters to complete such a reservation, including the number and types of terminals, line-speed, type of audio algorithm, start-time, end-time, video algorithm, type of network, along with other pertinent parameters. Providing these parameters presents a problem to both conference participants and service providers due to the fact that acquiring this information is difficult and providing this information makes the process of setting up or initiating a conference tedious and inconvenient. In addition, the customer must provide this information well in advance of the actual conference to reserve time and resources, and to allow adequate time to process the information and incorporate it into the conference set-up.
Furthermore, participants in an audio and/or multimedia conference may be spread all over the world and each may be using the services of a different Local Service Provider (LSP). Each LSP receives a part of the profit garnered by the multimedia service provider. Therefore, the service providers of audio and/or multimedia conferences find it desirable to use low cost trunking. IP trunking is often the least expensive communications trunking technology and therefore the service providers would ideally prefer using it. Also needed by audio and/or multimedia service providers is the ability to offer a single dial-in number for conference services, which is referred to as Single-Dial Conference Service Number (SDCSN). A SDCSN may be a regional or local number and may be different for users in different locations.